Internal combustion engine



P? 934. o. L. SNYDER ,9

INTERNAL COMBUSTION ENGINE Filed April 26, 1929 NVEN TOR. L. S'n der Patented Apr. 3, 1934 INTERNAL COMBUSTION ENGINE Oscar L. Snyder, Marysville, Mich.,

assignor, by

mesnc assignments, to Continental Aircraft Engine Company, a corporation of Delaware Application April 26, 1929, Serial No. 358,205

a 11 Claims. (oi. 123-152) This invention relates to internal combustion engines and refers more particularly to fuel mixture supply means or manifolds for engines of the radial cylinder type such as are now employed for aircraft.

An object of my invention resides in the provi sion of an improved manifold which will provide better fuel mixture distribution to the cylinders, thereby bettering the engine performance. In manifolds heretofore employed, such as the single inlet continuous ring type, certain cylinders tend to receive less of the fuel mixture than others. With my manifold I obtain a more equal and emcient distribution. Furthermore with my manifold I am enabled to secure a supercharger effect r by utilizing the gas momentum to advantage.

Referring to the accompanying drawing in which like reference characters represent corresponding parts,

Fig. 1 is a sectional elevation view through my manifold and associated engine, and 1 i Fig. 2 is a detail view of the manifold and carburetor connection.

In the drawing reference character A represents the engine having the usual cylinders arranged radially at axes 11 radiating from the horizontal crankshaft 12. In the illustration the engine has seven cylinders arranged in a plane perpendicular with the crankshaft although the 3 invention 'is of course not limited to any number of cylinders.

' B represents .the manifold which has outlets 1-, 2, 3, 4, 5, 6, 7, respectively communicating with cylinder conduits 13 extending to each cylinder head, the latter being valve controlled by the usual mechanism 14. The manifold outlets open to the main distributing portion 15 preferably circular in cross section. This portion 15 extends around the crankshaft axis so that it is substantially horseshoe shaped having non-communicating lower adjacent ends 16, 1'7, these ends preferably being formed with outlets 4 and 5 respec tivelyr Referring to Fig. 2 carburetor C supplies fuel mixture to manifold supply branches 18, 19 through the heater device 20 where desired. Branches 18 and 19 open into manifold inlets 21, 22 respectively intermediate outlets 3, 4 and 5, 6. With my manifold the fuel mixture is supplied with improved efliciency. For example suppose that the engine firing order is 1-3- 57-2- 4-6 and cylinder outlet 1 is supplying fuel mixture. Such mixture travels from branch. 19 clockwise in portion 15 to outlet 1 and counterclockwise from branch 18 in portion 15 to outlet 1. The next cylinder intakes before the preceding is closed so that the same directional effect of the mixture in portion 15 is utilized for outlet 3 thereby employing the inertia effect of the mixture to supercharge thesuccessivecylinders. Thetwobottomcylinders at 4 andb are least benefited by my system but with my arrangement the drainage of heavy fuel particles from the manifold portion 15 toward outlets 4 and 5 will generally balance their intake efficiency with the remaining cylinders.

Following out the intake period with the above suggested firing order it is apparent that when outlet 1 is drawing the charge from branches 18 and 19, the fuel mixture flows clockwise from branch 19 and counterclockwise from branch 18.

Cylinder outlet 3 being next in the firing order is supercharged because it is fed by'the' previously established clockwise fiow of fuel mixture from branch 19 and thepreviously established counterclockwise flow from branch 18. f However, cylinder 5 being next in the firing order, will not be supercharged as are the majority of the other cylinders (cylinder 6 likewise receiving less than a normal charge of supercharged fuel mixture) because of the fact that while the counterclockwise flow of mixture from branch 18 is the same as before in supplying outlets 1 and 3, the flow of mixture from branch 19 to outlet 5 is now no longer clockwise but must change to counterclockwise. The previously established clockwise flow of mixture between branch 19 and outlet 3 must therefore be opposed by the counterclockwise supply of mixture from branch 18 and thus the supercharging for outlet 5 is not realized. a

This deficiency in fuel mixture supply to outlet 5 is made up or compensated for by reason of the drainage of most of the heavy fuel par-. ticles thereinto, outlet 5 being at the lowermost point of the manifold.

The next cylinder in the suggested firing order is that associated with outlet '7 and it will be observed that this will be supercharged by reason of the previously established counterclockwise flow of mixture from branch 18, the mixture from branch 19 not contributing to the supercharging since the mixture from this branch must change in direction from counterclockwise (toward outlet 5) in opposition to the previously established counterclockwise flow of mixture from branch 18 for the relatively short distance between outlets 7 and 5. i

This is followed by flow of the mixture to outlet 2 which is supercharged by reason of the previously established clockwise flow from branch 19 and to a greater extent by the counterclockwise flow from branch 18, only a relatively small established counterclockwise flow of the fuel from branch 18 to outlet 2. Outlet 4, like outlet 5,

5 fuel mixture as compared with the degree-of supercharging realized by outlets 3, 5 and '7, for example.

The last cylinder in the firing order is that associated with outlet 6 which receives the fuel mixture from branch 19 in the same clockwise direction existent just previously. The proximity of outlet 6 to branch 19 will, of course, minimize the ramming effect of the fuel mixture flow as compared with that experienced for other of the manifold outlets. The flow of the mixture from branch 18 to outlet 6 is counterclockwise in opposition to the previous flow in the manifold with the result that outlet 6 is supplied with a somewhat less charge of fuel mixture than other of the cylinders. The net or overall gain in efficiency for the cylinders as a whole provides for greatly improved results in this art.

As the cycle of the firing order starts again, outlet 1 receives the fuel mixture by reason of the previously established counterclockwise flow from branch 18 while the flow from branch 19 is clockwise, the latter flow having only to overcome the previously established counterclockwise flow between the outlets. 1 and 7.

What I claim as my invention is:

1. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifolding device comprising a generally horseshoe-shaped main distributing portion forming a single duct having non-communicating ends, manifold conduits intermediate the respective cylinders and the main manifold portion, and fuel mixture supply means for the main manifold portion.

2. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifolding device comprising a generally circular main distributing portion forming a single duct having non-communicating ends, manifold conduits in-.

termediate the respective cylinders and the main manifold portion, and fuel mixture supply means for the main manifold portion.

3. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifolding device comprising a main distributing portion forming a single duct extending about the crankshaft axis and having non-communicating ends,

'manifold conduits intermed'ate the respective cylinders and the inain manifold portion, and fuel mixture supply means for the main manifold portion.

4. In an internal combustion engine having a plurality of cylinders radially arranged w;th respect to the engine crankshaft, a manifoldlng device comprising a generally horseshoe-shaped main distributing portion having non-communieating ends, manifold conduits intermediate the respective cylinders and the main manifold portion, and fuel mixture supply means for the main manifold portion, said non-communicating ends terminating in cylinder supply outlets.

5. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifolding device comprising a generallyhorseshoe-shaped main distributing portion forming a single duct having non-communicating ends, manifold corrduits intermediate the respective cylinders and the mainmanifold portion, and fuel mixture supply means for the main manifold portion extending downwardly from the main distributing portion of the manifold.

6. In an internal combustion engine having a plurality of cylinders radially arranged with respect. to the engine crankshaft, a manifolding device comprising a generally horseshoe-shaped main distributing portion forming a single duct having non-communicating ends, manifold conduits intermediate the respective cylinders and the main manifold portion, and fuel mixture supply means for the main manifold portion, a carburetor, and branched conduits intermediate the carburetor and main distributing portion of the manifold.

'7. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifolding device comprising a generally horseshoe-shaped main distributing portion having non-communicating ends, manifold conduits intermediate the respective cylinders and the main manifold portion, and fuel mixture supply means for the main manifold portion, said non-communicating ends terminating in cylinder supply outlets, and'fuel mixture supply branches communicating with the main distributing portion adjacent the said cylinder supply conduits at the non-communicating ends.

8. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifolding device comprising a generally horseshoe-shaped main distributing portion having non-communicating ends, manifold conduits intermediate the respective cylinders and the main manifold portion, the fuel mixture supply means for the main manifold portion, said non-communicating ends terminating in cylinder supply outlets, and fuel the said cylinder supply conduits at the noncommunicating ends.

- 9. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifold consisting of a single duct extending generally about the crankshaft axis and having a. plurality of substantially equally spaced cylinder outlets, said manifold having an end terminating in a single cylinder outlet arranged to drain a portion of the manifold of wet fuel particles.

10. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifold extending generally about the crankshaft axis and having a plurality of substantially equally spaced cylinder outlets, said manifold having an end terminating in a single cylinder outlet arranged to drain a portion of the manifold of wet fuel particles, and fuel mixture inlet means for the manifold above and adjacent said end outlet.

11. In an internal combustion engine having a plurality of cylinders radially arranged with respect to the engine crankshaft, a manifold device including a single duct having fuel mixture inlet means and separate outlet means for each of the respective cylinders, successive outlets in the engine firing order being arranged to utilize the inertia of the fuel mixture in the manifold device for producing a supercharging effect.

OSCAR L. SNYDER. 

